Hybrid vehicles are attracting attention as environment-friendly vehicles. A hybrid vehicle incorporates a power storage device, an inverter, and an electric motor driven by the inverter, in addition to a conventional internal combustion engine, as the power source for traction
Such a hybrid vehicle is provided with a catalyst device, as long as an internal combustion engine is mounted, for the purpose of purifying the exhaust gas from the internal combustion engine, likewise with a conventional vehicle that incorporates just an internal combustion engine as the driving source. A catalyst device can generally purify the regulation-subject component in the exhaust gas at the point of time when the catalyst temperature is increased by the exhaust gas of the internal combustion engine and the catalyst is activated. In other words, the catalyst device must be warmed up prior to use.
Japanese Patent Laying-Open No. 2008-163867 (PTL 1) discloses a method that can improve the regulation-subject component discharged during warm-up of a catalyst device in a hybrid vehicle. When a determination is made that the catalyst device is currently warmed up at the hybrid vehicle, running at a power mode that is one of a plurality of running modes is prohibited. Accordingly, increase of the exhaust gas from the internal combustion engine is suppressed. Therefore, the regulation-subject component that will be discharged without being processed sufficiently by the catalyst of the catalyst device can be improved (refer to PTL 1).